An ultra-high-capacity aircraft such as Airbus A380 weighs 560 tonnes, and its big body must be supported by two tires at a nose landing gear and twenty tires at a main landing gear, that is, twenty two tires in total. An internal pressure of the tire used for such an aircraft is six or more times higher than a tire for a passenger car, so that measures for improving material quality of the aircraft tire, its surface structure etc. have been taken.
When an aircraft is in a landing process, an aircraft wheel remains stationary before touchdown, so that high pressurized friction is generated between a runway and the tire until rotating speed of the wheel matches a rotating speed (hereinafter referred to as a target rotating speed VA) which is consistent with a flying speed of the aircraft making the touchdown (for example, about 250 km/h). Because of the high pressurized friction, the tire contacts the runway while heated to a considerably high temperature, which results in tire wear enough to leave a rubber tire burn mark on the runway.
To solve such a problem, a technique such as follows is proposed. A plurality of curved vanes are arranged on a side of a tire body for receiving flight wind pressure. Through the action of the flight wind pressure received by the curved vanes, an aircraft wheel is rotated ahead of the touchdown in a direction in which it rotates during a landing roll (refer to, for example, Japanese Patent Unexamined Publication No. H09-254892).
According to the technique disclosed in the above-mentioned Japanese Patent Unexamined Publication No. H09-254892, by the action of the flight wind pressure received by the curved vanes arranged on the side of the tire body, the aircraft wheel is rotated ahead of the touchdown in the direction in which it rotates during the landing roll, so that the pressurized friction between the runway and the tire can be reduced substantially during the landing of the aircraft, thus allowing suppression of the rubber tire wear which occurs during the landing.
However, the technique disclosed in this Japanese Patent Unexamined Publication No. H09-254892 has the following problem. When the landing is made with the rotating speed of the wheel ahead of the touchdown exceeding the target rotating speed VA, a shock that accelerates the aircraft is generated at the touchdown. On the other hand, when the landing is made with the rotating speed of the wheel ahead of the touchdown not reaching the target rotating speed VA, a shock that decelerates the aircraft is generated at the touchdown.
The present invention is directed toward solving the problems discussed above and aims to provide an aircraft tire capable of suppressing rubber tire wear which occurs during landing as well as shocks that accelerate or decelerate an aircraft at touchdown.